The present invention relates to the collection of samples, including uses and observations made thereof.
The ability to accurately and reliably determine the presence or otherwise of a particular sample (e.g., compound, agent, molecule, chemical, gas, toxin, metal, drug) on an everyday object is of significant importance to customs and police forces around the world. The samples of interest include illicit drugs and explosives and it is their detection in both a forensic context and with regard to the detection of contraband or tariff evasion that is of interest to police and custom forces respectively. Generally, the samples of interest are likely to be present only in extremely small, or trace amounts. Consequently, extremely sensitive chemical analysis techniques are employed to determine the presence or otherwise of a particular compound (target compound analysis).
One such analytical approach known from the prior art is to use a Tandem Mass Spectrometer to chemically analyse a collected sample. However, the prior art techniques for analysing collected samples, and more particularly in the preparation of the samples prior to analysis by the Mass Spectrometer, can be both complex and time consuming. For example, bank notes are sampled by taking bundles of bank notes and shaking them over a sheet of aluminium foil. Any particles deposited on the foil are then vacuumed up, the vacuum including a removable filter, and the filter sampled using the Tandem Mass Spectrometer. To sample each filter generally requires extensive sample preparation and sometimes chemical treatment prior to analysis. Consequently, the sample collection process is both complex and time consuming.
Whilst such sample collection techniques may be appropriate when a suspect object has already been identified, for example by virtue of being found in the possession of a suspected criminal, they are not applicable for collecting samples from a large number of items to identify a suspect item. A typical example of where such a requirement is experienced is in checking the baggage of travellers in an airport, train station, a cruise ship embarkation terminal or any other transportation terminal or security check point in which large numbers of people and their bags need to be processed quickly and efficiently. In such circumstances the prior art sampling techniques and apparatus do not allow individual items of baggage to be sampled in a time effective manner.
One of the difficulties in sampling certain objects (e.g., baggage) for the presence of unwanted samples (e.g., explosives, drugs, toxins, illicit compounds, counterfeit materials, gases, etc.) is actually retrieving a sample from the object and presenting those samples to a suitable detector, such as a Mass Spectrometer or other device. In many cases, it is difficult to get into the various corners and recesses of the objects or items to be sampled, whilst avoiding cross contamination from one object or item to another. Similarly, it is difficult to remove the samples from the sampling devices and achieve acceptable levels of sensitivity to various particles of the sample. Accordingly, there remains a need for improved methods and devices for sampling objects.